The present invention is directed to a process of forming secondary amines from olefinic hydrocarbons and ammonia. The resultant product can be a lower hydrocarbyl amine or a fatty amine, as desired, depending of the starting olefin.
Lower aliphatic amines are generally prepared by one of four commercial processes. In one process, alcohols are reacted with ammonia in the presence of a dehydrating agent, such as alumina to produce a primary, secondary or tertiary amine depending on the ratio of reactants used. A second commercial method comprises reacting an alcohol with ammonia in the presence of hydrogen and a hydrogenation catalyst, such as nickel. This method normally produces a mixture of amines.
A third method requires the reaction of aldehydes and butanes with ammonia and hydrogen in the presence of a hydrogenation catalyst such as copper or nickel. Again, the product is a mixture of amines. Finally, the commercial method of forming fatty amines is accomplished by reacting a fatty acid or its ester with ammonia to form the nitrile and then hydrogenating the nitrile to form the amine. Secondary amines require the exclusion of water, high reaction temperatures and venting of residual ammonia.
Catalytic alkylation of organic amines with an olefin, carbon monoxide and hydrogen to form tertiary amines was initially disclosed by Reppe in Experiention, Vol. 5, p. 93 (1949); German Pat. No. 839,800 (1952); and Liebigs Ann. Chem., Vol. 582, p. 148 (1953). The process had limited value due to the required use of large quantities of iron or nickel carbonyls as the catalyst, the slow rate of reaction and poor yields. Further, the process was directed at the formation of tertiary amines.
Similarly, U.S. Pat. Nos. 2,422,631; 3,234,283; 3,513,200; and 4,096,150 each disclose systems which permit catalytic alkylation of certain amines to form tertiary amino compounds.
It is highly desired to find a simple one step process which is capable of forming secondary amines and, further, which is capable of forming fatty secondary amines having either odd and even number of carbon atoms per hydrocarbyl chain.